To enable two neighboring communication devices to communicate with each other, the two devices are connected by using a pair of optical modules and an optical fiber. As a transmission distance of the optical module increases, laser power of a laser in the optical module becomes increasingly high. In a scenario such as that in which no optical fiber is inserted in an optical fiber interface of the optical module or a fiber cut occurs in an optical fiber, a leaked high-power laser beam may cause human bodily injury or eye injury.
In the prior art, the problem of human bodily injury caused by a laser beam leakage of an optical module is resolved by means of intelligent power adjustment (IPA). FIG. 1 is a schematic diagram of an IPA process when a fiber cut occurs in an optical fiber line in the prior art. As shown in FIG. 1, when a fiber cut occurs at a point L in a line, a detection board at an end B detects a receiving loss of signal (RLOS) alarm and turns off a laser of a control board at the end B. In this way, a detection board at an end A is further triggered to detect the RLOS alarm, and then a system at the end A turns off a laser of a control board. In this case, there is no optical power in an optical fiber of a line between the end A and the end B. After IPA is started, the laser of the control board sends a probe laser beam to detect whether the line returns to normal. That is, a probe laser beam is sent after the control board at the end B is turned off for a period of time, and after the probe laser beam is received at the end A, the RLOS alarm is ended, so that the laser of the control board at the end A is turned on. In this case, if the optical fiber returns to normal, the RLOS alarm at the end B is ended, and further, the entire system resumes normal transmission.
However, the solution in the prior art can only perform, with an optical fiber being inserted, control to turn on or turn off a laser by means of a complete loop, and cannot resolve the problem of human bodily injury caused by a laser beam leakage of an optical module in a scenario in which no optical fiber is inserted in an optical fiber interface.